Megasonic cleaning is one of the most widely used wet-cleaning processes in the semiconductor, hard disk and flat panel display industries. Presented results involve different and new techniques for introducing the high frequency ultrasonic energy in the cleaning bath. The effects of power, temperature and time on the removal efficiency of Si3N4 particles in the size range from 0.1 mu m to 1.0 mu m from silicon wafers are presented. Results show that removal efficiencies near 100% for silicon nitride particles using deionized water could be achieved under the right conditions. The megasonic input power has a greater effect on the removal efficiency than does temperature.